import time
incomplete_sign = 50
print('='*23+'开始下载'+'='*25)
for i in range(incomplete_sign + 1):
    completed = "*" * i
    incomplete = "." *(incomplete_sign - i)
    percentage =(i / incomplete_sign) * 100
    print("\r{:.0f}%[{}{}]".format(percentage,completed,incomplete),end="")
    time.sleep(0.5)
    print("\n" + '='*23+'下载完成'+'='*25)